[Task]: update unit testing docs

[bamaer]

What needs to happen?

Outdated (and probably incorrect) information in:
https://hop.apache.org//manual/latest/pipeline/pipeline-unit-testing.html

Incorrect "Unit test base path" description (base folder for pipelines to test, not where unit tests are stored):
https://hop.apache.org//manual/latest/projects/projects-environments.html

Issue Priority

Priority: 3

Issue Component

Component: Documentation

[bamaer]

.take-issue